Tuesday, May 28, 2013

Adirondack Wildlife: The Porcupine Gives Birth

Porcupine Baby PorcupetteJune is the month when many forms of wildlife give birth in the Adirondacks. The last week in May and early June marks the start of a nearly four month long interval of weather favorable for birth and the period of development following birth that young birds, mammals, some reptiles, fish and bugs need before they are mature enough to successfully contend with the life threatening challenges posed by the change in seasons.

Among the creatures that bear their young shortly after Memorial Day is the porcupine, a large and cold-hardy rodent known for its unique system of defense.

Despite its relatively large size, the porcupine tends to restrict its daily routine to a small area in which there is a suitable supply of food and shelter. Like the beaver and some species of voles, this gnawing animal is a strict herbivore that only ingests certain parts of specific plants, especially during the colder months of the year. As the growing season arrives and foliage emerges from buds on twigs and shoots from the soil, this slow moving denizen of the deep woods expands its diet but is still very selective about the items it consumes. Once an adult porcupine finds a patch of forest with an abundance of food, it remains in that home range which may be only a dozen acres in size.

Shelter for this solitary rodent is often found in a large cavity of a standing tree, within a sizeable hollow log on the ground, or in the recesses of a rock enclosure formed by a pile of cracked boulders. While the male porcupine may refrain from using a shelter during much of the year, the female inevitably seeks out some type of den when the time approaches for her to give birth. Bedding material is usually absent on the floor of a porcupines den, however, a small mass of cushiony material is assembled prior to giving birth around the spot where her single infant is pushed from her body.

The newborn is completely enclosed by a thin, placental sac that tears open immediately after being expelled by the female’s body. Since the quills of the infant are still soft, moist and flexible for the first hour after birth, and pose no harm to the mother as her baby enters the world, this slippery sac is believed by some naturalists to allow for an easier birthing process. At birth, the baby, referred to as a porcupette, averages a foot in length and one pound in weight. An adult female, which is slightly smaller than a male, averages two and a half feet in length, and normally weighs between 10 to 14 pounds. In terms of relative size, a the process of birth in the porcupine would be roughly equivalent to a 140 pound human having a nearly 12 pound infant.

Although the porcupine has thousands of sharp-pointed, barb-tipped quills covering its back, sides and tail, this mammal has the ability to raise and lower these natural needles using tiny muscles near the surface of its skin. This allows the mother to pull her quills flat against her body so they will not pose any harm to her baby. Since the underside of a porcupine’s body lacks quills, her baby is able to snuggle against her chest and belly to access her mammary glands for the protein enriched milk without much effort. In a similar way, the porcupette instinctively pulls its quills close to its body when in contact with its mom.

Should a stray quill happen to accidentally penetrate the skin of another porcupine, the affected animal is often capable of reaching around and biting off the very tip of this hollow hair, which causes it to deflate slightly. The animal then attempts to pull it out with its mouth. The skin of a porcupine is known to contain natural antibiotics that help prevent infections to the spot where one or several of these defensive weapons pierce the animal’s hide.

For the first two weeks after birth, the porcupette regularly nurses on its mother’s milk, but instinctively and quickly begins to gnaw on various plants around its den. Because of the porcupette’s quills, there are very few predators that bother this wildlife baby when it ventures from its den. The fisher is well known as the main natural enemy of the porcupine, however, the coyote, bobcat and great horned owl can also successfully attack and kill porcupettes that they encounter in the wilds.

When confronted by a predator, a porcupine has to pull its quills upward. Occasionally a young animal is unable to respond fast enough, or is unable to prevent an attacker from getting in front of it and grabbing it by the throat or head where it lacks quills.

Baby animals seen alone should never be disturbed by a passing person. All of these infants have a mother feeding close by and are simply learning about their surrounding. All wildlife babies, including the porcupine, are great to watch from a distance and photograph; just don’t touch!

Photo: A porcupette recently birthed at Switzerland’s Zoo Basel.


Tom Kalinowski

Tom Kalinowski is an avid outdoor enthusiast who taught field biology and ecology at Saranac Lake High School for 33 years.

He has written numerous articles on natural history for a variety of magazines and wrote a weekly nature column for the Lake Placid News for nearly ten years.

Tom has also written several books which focus on various events that occur among the region’s flora and fauna during very specific times of the calendar year. Along with writing, he also spends time photographing wildlife.




One Response

  1. Lily says:

    Tom, thanks for this excellent and detailed article. I always read your posts from beginning to end.